Added docs for replace() and replace1().
diff --git a/Doc/lib/libstring.tex b/Doc/lib/libstring.tex
index 80222c1..284782a 100644
--- a/Doc/lib/libstring.tex
+++ b/Doc/lib/libstring.tex
@@ -227,6 +227,19 @@
width is reached. Strings starting with a sign are handled correctly.
\end{funcdesc}
+\begin{funcdesc}{replace}{old, new, str}
+Return a copy of string \var{str} with all occurrences of substring
+\var{old} replaced by \var{new}.
+\end{funcdesc}
+
+\begin{funcdesc}{replace1}{old, new, str\optional{, start\optional{, end}}}
+Return a copy of string \var{str} with the first occurrence of
+substring \var{old} replaced by \var{new}. If no occurrence is found,
+\var{str} is returned unchanged. Optional arguments \var{start} and
+\var{end} limit the search for \var{old} like for \code{find} (they
+are not used to slice the result).
+\end{funcdesc}
+
This module is implemented in Python. Much of its functionality has
been reimplemented in the built-in module \code{strop}. However, you
should \emph{never} import the latter module directly. When